California: Porcelain, Ceramics Not “Artificial Stone”

SACRAMENTO, Calif. – Proposed changes to California’s workplace-safety standards will exempt porcelain and ceramic materials from rules on fabricating manufactured stone products.

The exemption is one of the major alterations suggested for the state’s rules concerning worker exposure to crystalline silica, along with defining respirator use and certain exemptions for different types of fabrication.

The proposed changes are currently in a 15-day public-comment period set to expire on Nov. 13. A date for final action by the state’s Occupational Safety and Health Standards Board is yet to be determined.

The changes affect the emergency standards on crystalline-silica exposure adopted by the board late last year.

The definition of “artificial stone” now includes porcelain, along with “reconstituted, artificial, synthetic, composite, engineered or manufactured stone.” The proposed change would take porcelain out of the definition and include the following new phrase: “Fired ceramic porcelain tiles and panels are not artificial stone.”

The changes also revise the definition of “high-exposure trigger task” that requires fabricators to follow the exposure rules with materials containing crystalline silica. The rules remain for artificial stone containing, by weight, more than 0.1% of crystalline silica; a revision would add “other silica containing products” to the current requirement with natural stone containing more than 10$ crystalline silica by weight.

New general exemptions include geologic field research, quarries, concrete/cement plants, ceramic/porcelain manufacturing, and funereal products (monuments, tombstones, etc.) as long as exposure is kept below certain levels.

The changes also exempt “tasks other than the fabrication of countertops, backsplashes, walls, flooring, waterfall countertop edges and other products from slabs or panels” if exposure is kept below certain levels.

Proposed changes would also offer exceptions to using respirators in regulated areas defined by the rules, as long as exposures are “less than five minutes in an eight-hour time period” and silica levels remain under a certain level.

Comments need to be made by 5 p.m. on Nov. 13 to the standards board office in Sacramento. Only comments related directly to the proposed changes will be considered.

Download the proposed changes.